During engine operation, combustion gas may leak between the cylinder and its piston rings into the engine crankcase. The leaked combustion gas is referred to as piston blowby gas and may comprise unburned intake air/fuel mixture, exhaust gas, oil mist, and water vapor.
A crankcase ventilation system be it PCV or CCV, is typically employed to ventilate the crankcase and recirculate the blowby gas to the intake side of the engine for burning the gas in the combustion chamber. The PCV/CCV system takes advantage of the negative pressure in the intake to draw the gas out of the crankcase and may utilize a PCV/CCV valve to regulate the flow.
At low ambient temperatures, such as in cold weather climates, a common concern is freezing of the water vapor component of the blowby gas in the PCV/CCV system. To minimize the risk of freezing, some PCV/CCV systems may include a PCV/CCV heater, an extra hot water-carrying hose routed adjacent the PCV/CCV hose, or electrically heating or insulating the PCV/CCV hose. Each of these solutions add a significant additional cost to a PCV/CCV system. Furthermore, the system might not be necessary in the operating environment of the moment, but the system must be capable of operating at all design temperature extremes.
Even with some heating systems, freezing can still occur at the outlet of the PCV/CCV system where blowby gas is introduced into the intake side of the engine. Ice build-up at this location can damage engine components downstream, such as a turbocharger compressor/impeller wheel or throttle control valve. Even if damage is avoided, ice-build-up can cause restrictions in the engine intake which may affect engine performance or fuel economy.
As such, the need exists for a simple PCV/CCV system that reduces or eliminates ice build-up in low ambient temperature environments without adding substantial cost or complexity to the engine.